Controlled ablation and surface modification for marking an electronic device

ABSTRACT

An article having a laser-formed marking is disclosed. The article includes a coating defining an exterior surface of the article and the marking extends through the coating. The marking comprises a recessed marking feature which provides a color or other visual attribute to the marking.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation patent application of U.S. patentapplication Ser. No. 16/547,212, filed Jun. 28, 2019 and titled“Controlled Ablation and Surface Modification for Marking an ElectronicDevice,” which is a nonprovisional patent application of and claims thebenefit of U.S. Provisional Patent Application 62/693,842, filed Jul. 3,2018 and titled “Controlled Ablation and Surface Modification forMarking an Article,” U.S. Provisional Patent Application 62/753,027,filed Oct. 30, 2018 and titled “Controlled Ablation and SurfaceModification for Marking an Article,” and U.S. Provisional PatentApplication 62/816,769, filed Mar. 11, 2019 and titled “ControlledAblation and Surface Modification for Marking an Electronic Device,” thedisclosures of which are hereby incorporated herein by reference intheir entireties.

FIELD

The described embodiments relate generally to forming a marking on anarticle or component for an electronic device. More particularly, thepresent embodiments relate to forming a marking including a relieffeature which extends at least partially through a coating that definesan exterior surface of the article or component of the electronicdevice.

BACKGROUND

Articles such as electronic devices generally include an exteriorcomponent, such as a housing, that may be marked or printed. Sometraditional marking techniques form letters or glyphs using lines ofink. Such markings may be subject to wear over the lifetime of thedevice.

Embodiments described herein are directed to markings for articles suchas electronic devices that may have advantages as compared to markingsproduced by some traditional techniques. In embodiments describedherein, the article includes a coating along an exterior surface and themarking includes a marking feature recessed with respect to the coating.A recessed marking feature may provide a color or other visual attributeto the marking. The markings described herein can provide a distinctiveappearance to the article and may also provide improved durability oversome traditional ink or paint based marking techniques. In general, themarkings formed using the described techniques may not suffer from thedrawbacks associated with some traditional ink-based marking techniques.

SUMMARY

Embodiments described herein relate to markings formed along an exteriorsurface of an article, articles including the markings, and techniquesfor forming the markings. The marking may be in the form of an image, apattern, text, a glyph, a symbol, an indicia or a geometric shape. Inembodiments, the marking extends through a coating defining an exteriorsurface of the article and visually contrasts with the coating. Themarking may be formed using a laser to allow precise removal of thecoating in the marking area and to give a color or other visualattribute to the marking.

In aspects of the disclosure, the article comprises a device componentand the marking is formed on the device component. In additionalaspects, the article is an electronic device or a component of anelectronic device. The device component may comprise a metal material,such as a metal or a metal alloy. The device component may furthercomprise a coating formed over a surface, such as a front surface, ofthe metal material. The coating may be a multilayer coating.

In further aspects, the marking comprises a recessed marking featurewhich provides a color or other visual attribute to the marking. By theway of example, the recessed marking feature is recessed with respect toan exterior surface of the article and defined along an exterior surfaceof the metal material.

In further aspects, the recessed marking feature is included in a relieffeature, which may be laser-formed. The relief feature may furtherinclude at least one recess wall that partially defines a recess. Therecess may extend through all or a portion of a thickness of thecoating. In additional aspect, the marking may comprise additionalfeatures, such as a laser-formed color feature formed within thecoating.

In embodiments, an electronic device comprises a device componentcomprising a metal substrate, a coating layer formed along at least afront surface of the metal substrate, and a marking. The coating layercomprises a first layer disposed over the front surface of the metalsubstrate and comprising a polymer binder and inorganic pigmentparticles dispersed within the polymer binder. The coating layer furthercomprises a second layer disposed over the first layer and comprising atransparent polymer defining at least a portion of an exterior surfaceof the electronic device. The marking is formed along an exteriorsurface of the electronic device and comprises a laser-formed relieffeature. The laser-formed relief feature has at least one recess wallpartially defining a recess extending through the first layer and thesecond layer of the coating. The laser-formed relief feature further hasa recessed marking feature defining a bottom of the recess and visuallydistinct from an adjacent portion of the coating layer.

The recessed marking feature may include a geometric feature, a colorfeature, and/or a texture feature formed in the front surface of themetal substrate as described in the present disclosure. The recessedmarking feature may include at least one geometric feature, such as agroove or channel, formed into the exterior surface of the metalmaterial. As another example, the recessed marking feature may include acolor feature having a structural color. For example, a metal oxidelayer may be formed on the exterior surface of the device component andhave a thickness which imparts a color to the marking (marking color),such as through interference of light. As an additional example, therecessed marking feature may include a texture feature, such as asurface finish defining a roughness of the recessed marking feature. Therecessed marking feature may also include combinations of thesefeatures. In aspects described herein, the marking comprises at leasttwo recessed marking features.

In additional embodiments, an electronic device comprises a devicecomponent comprising a metal material, a multilayer coating formed overa surface of the metal material, and a marking formed into themultilayer coating. The multilayer coating comprises a first layerdisposed over the surface of the metal material and comprising a binderand pigment particles dispersed within the binder. The multilayercoating further comprises a second layer disposed over the first layerand comprising a transparent polymer. The marking comprises a firstrecessed marking feature along a surface of the metal material andvisually distinct from the multilayer coating. The marking furthercomprises a laser-formed relief feature at least partially surroundingthe first recessed marking feature. The relief feature has a recess wallpartially defining a recess, the recess extending through the firstlayer and the second layer of the multilayer coating. The laser-formedrelief feature further has a second recessed marking feature visuallydistinct from an adjacent portion of the multilayer coating anddefining, in part, a bottom of the recess.

Each of the first and the second recessed marking features may include ageometric feature, a color feature, and/or a texture feature asdescribed in the present disclosure. The second recessed marking featuremay be visually distinct from the first recessed marking feature. Thefirst recessed marking feature may also define, in part, a bottom of therecess. For example, the first recessed marking feature may include acolor feature and the second recessed marking feature may include ageometric feature which forms a complete or partial perimeter around thefirst recessed marking feature.

The present disclosure also relates to methods for forming a markingalong an exterior surface of an article such as an electronic device ora component for an electronic device. In aspects of the disclosure, amultilayer coating defines the exterior surface of the electronic deviceand the marking includes a laser-formed relief feature comprising arecessed marking feature and a recess wall at least partially defining arecess in at least a portion of the multilayer coating.

In embodiments, the methods of forming the marking produce little, ifany, damage to the multilayer coating adjacent the recessed markingfeature. For example, the methods may not change the color and/ortexture of the recess wall of the relief feature to an extent visuallydiscernable by the human eye at a normal viewing distance. As anotherexample, the methods n may produce a recess wall and an adjacent portionof the multilayer coating which have no cracks visually discernable tothe human eye at a normal viewing distance.

In aspects of the disclosure, the relief feature may be formed using alaser-based treatment as described herein. The laser-based treatment mayinclude at least two different laser-based treatment operations. The atleast two different laser-based treatment operations may involve twodifferent lasers or a single laser operated at two different processconditions.

In embodiments, a method for forming a marking comprising a relieffeature along an exterior surface of an electronic device comprisesremoving, using a first laser, a portion of a multilayer coating to forma recess through the multilayer coating and expose a metal portion of asubstrate. The multilayer coating is formed over a surface of thesubstrate and comprises a first layer comprising a binder and inorganicpigment particles dispersed within the binder and a second layercomprising a transparent polymer. The method further comprises modifyingthe metal portion, using a second laser, to create a recessed markingfeature of the relief feature. The recessed marking feature comprises atleast one of a geometric feature formed into the metal portion or acolor feature formed on the metal portion.

The operation of modifying the metal portion may include one or more oflaser texturing and laser coloring the metal portion. The operation ofmodifying the metal portion may further include laser shaping the metalportion. As previously discussed, in embodiments the operation ofmodifying the metal portion produces little, if any, damage to themultilayer coating adjacent the recessed marking feature.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will be readily understood by the following detaileddescription in conjunction with the accompanying drawings, wherein likereference numerals designate like elements.

FIG. 1A shows an example article with a marking in accordance withembodiments herein.

FIG. 1B shows an enlarged view of the marking of FIG. 1A showing a topview of a relief feature.

FIG. 1C shows an enlarged view of the marking of FIG. 1A showing a topview of another relief feature.

FIG. 1D shows an example of a cross-sectional view of the marking ofFIG. 1C.

FIG. 1E shows another example of a cross-sectional view of the markingof FIG. 1C.

FIG. 2 shows a schematic cross-sectional view of an example markingcomprising a recessed marking feature including a geometric feature.

FIG. 3 shows a schematic cross-sectional view of an example markingcomprising a recessed marking feature including multiple geometricfeatures.

FIG. 4 shows a schematic cross-sectional view of another example markingcomprising a recessed marking feature including a geometric feature.

FIG. 5 shows a schematic cross-sectional view of an additional examplemarking comprising a recessed marking feature including a geometricfeature.

FIG. 6A shows a schematic cross-sectional view of an example markingcomprising a recessed marking feature including a metal oxide layer.

FIG. 6B shows a schematic cross-sectional view of another examplemarking comprising a recessed marking feature including a metal oxidelayer.

FIG. 7 shows a schematic cross-sectional view of an example markingcomprising a geometric feature and a recessed marking feature includinga metal oxide layer.

FIG. 8 shows a schematic cross-sectional view of an additional examplemarking comprising a recessed marking feature including a geometricfeature and a metal oxide layer.

FIG. 9 shows a schematic cross-sectional view of a further examplemarking comprising a recessed marking feature including a geometricfeature and a metal oxide layer.

FIG. 10A shows an enlarged view of an additional example marking showinga top view of a relief feature.

FIG. 10B shows a schematic cross-sectional view of the marking of FIG.10A.

FIG. 11A shows an enlarged view of a further example marking showing atop view of a relief feature.

FIG. 11B shows an enlarged view of another example marking showing a topview of a relief feature.

FIG. 11C shows an enlarged view of an additional marking showing a topview of a relief feature.

FIG. 12 shows a flowchart of an example process for making a marking.

FIGS. 13A, 13B, 13C, and 13D schematically show stages in an exampleprocess for making a marking.

FIG. 14 shows a flowchart of an additional example process for making amarking.

FIG. 15 shows a flowchart of another example process for making amarking.

FIG. 16 shows a schematic representation of an electronic device.

The use of cross-hatching or shading in the accompanying figures isgenerally provided to clarify the boundaries between adjacent elementsand also to facilitate legibility of the figures. Accordingly, neitherthe presence nor the absence of cross-hatching or shading conveys orindicates any preference or requirement for particular materials,material properties, element proportions, element dimensions,commonalities of similarly illustrated elements, or any othercharacteristic, attribute, or property for any element illustrated inthe accompanying figures.

Additionally, it should be understood that the proportions anddimensions (either relative or absolute) of the various features andelements (and collections and groupings thereof) and the boundaries,separations, and positional relationships presented therebetween, areprovided in the accompanying figures merely to facilitate anunderstanding of the various embodiments described herein and,accordingly, may not necessarily be presented or illustrated to scale,and are not intended to indicate any preference or requirement for anillustrated embodiment to the exclusion of embodiments described withreference thereto.

DETAILED DESCRIPTION

Reference will now be made in detail to representative embodimentsillustrated in the accompanying drawings. It should be understood thatthe following descriptions are not intended to limit the embodiments toone preferred implementation. To the contrary, the described embodimentsare intended to cover alternatives, modifications, and equivalents ascan be included within the spirit and scope of the disclosure and asdefined by the appended claims.

The following disclosure is generally related to forming a marking alongan exterior surface of an article. In embodiments, the marking extendsthrough a coating defining the exterior surface of the article. Themarking may include laser-formed relief feature having a marking featurewhich is at least partially recessed with respect to the coating. Therelief feature may further include a recess wall that partially definesa recess. In aspects of the disclosure, the article is an electronicdevice or a component of an electronic device.

The techniques described herein use a laser to form the marking. Inaspects of the disclosure, the techniques use a laser to form a relieffeature. The laser parameters may be specially adapted to limit orprevent visual defects or cracks within the coating due to thermaleffects from the laser. Further, techniques described herein may beadapted to limit removal and/or roughening of a metal materialunderlying the coating during formation of the recess. Therefore, thelaser-based marking techniques described herein may provide an advantageover some traditional techniques which may produce greater disruption ofthe coating and/or the surface of the metal substrate. As examples, thelaser-based marking techniques described herein may provide an advantageover some mechanical engraving or chemical etching techniques. Inaddition, the laser-based techniques described herein can form recessedmarking features having at least one dimension which is micro-scale ormilli-scale.

The marking may be in the form of an image, a pattern, text, a glyph, asymbol, an indicia, or a geometric shape. As examples, geometric shapesinclude, but are not limited to lines, curves, and shapes such ascircles, ovals, and polygons. Polygons include, but are not limited to,triangles, squares, rectangles, pentagons, and hexagons.

The marking may comprise a relief feature which is, in part, recessedwith respect to an exterior surface of the coating. For example, therecessed marking feature may be recessed with respect to the exteriorsurface of the coating. The relief feature may have a depth less than 1mm, less than 500 μm, from about 100 μm to about 500 μm, from about 50μm to about 150 μm, or from about 5 μm to about 30 μm. In aspects, therelief feature has a width from about 20 μm to about 100 μm, less thanabout 1 mm, less than about 1 cm, or less than about 5 cm. Typically,the relief feature is a blind feature and does not extend through thedevice component.

The relief feature may further comprise one or more recess wallsdefining a recess in the coating, with the recessed marking featurepositioned at least partially below the recess. For example, the relieffeature may comprise a pair of recess walls defining a recess in thecoating. The recessed marking feature may define a bottom of the recess.The relief feature may further comprise a perimeter at the exteriorsurface of the coating and may be formed using a laser-based treatmentas described herein.

The visual appearance of the marking and the coating may differ in orderto provide visual contrast. For example, the recessed marking featuremay provide a reflectance and/or color which differs from that of anexterior surface of the coating. In addition, the recessed markingfeature may include a geometric feature which is visually discernable.The recessed marking feature may be formed along an external surface ofa metal material. The metal material may form a portion or a whole of asubstrate. For example, the substrate may be formed of a metal material,in which case the substrate may be referred to as a metal substrate. Therecessed marking feature may also be formed along an external surface ofa metal portion of the substrate.

By way of example, visually discernable geometric features may be formedas depressions, protrusions, holes, or other geometric forms relative toan exterior surface of the metal material. By the way of example, ageometric feature may have a depth of from 10 μm to 500 μm. The recessedmarking feature may include one or more grooves or channels forming adepression in an exterior surface of the metal material. In addition,the recessed marking feature may include a depression whose perimeterdefines a circular, oval, or polygonal shape.

In embodiments, a groove or channel may have a width that is narrowrelative to a width of the recessed marking feature. For example, agroove or channel may have a width that is less than about 20% or lessthan about 10% of the width of the recessed marking feature. As anadditional example, a groove or channel may have a width that is greaterthan about 20% of the width of the recessed marking feature and lessthan or equal to the width of the recessed marking feature. As furtherexamples, a groove may be v-shaped or u-shaped in cross-section 123. Asused herein, the terms “about” and “approximately” are used to accountfor relatively small variations, such as a variation of +/−10%, +/−5%,or +/−2%. As examples, a width of a groove or channel may be greaterthan its depth, equal to its depth, or less than its depth. Inembodiments, a depth of a groove or channel is less than a thickness ofthe coating.

A groove or channel may take a variety of forms. For example, a groovemay form a perimeter around a portion of the recessed marking feature.Additional features of the marking, such as a texture feature (e.g., asurface finish) or a color feature (e.g., a metal oxide layer), maytherefore be inward from this perimeter. The recessed marking featuremay also include a pattern of multiple grooves. For example, therecessed marking feature may include multiple grooves aligned to form ahatching pattern. As another example, the marking feature may include afirst set of grooves aligned to form a first hatching pattern and asecond set of grooves aligned to form a second hatching pattern which isangled with respect to the first hatching pattern, thereby forming acrosshatching pattern. As another example, a geometric feature such asan angle or groove may be formed in the surface of the metal material inorder to present a region of the recessed marking, at a particular anglewith respect to a horizontal plane.

In additional aspects, a geometric feature may provide a degree ofisolation between a recess wall of the relief feature and a region ofthe recessed marking feature which is to undergo a laser-basedtreatment. Inclusion of such a geometric feature in the recessed markingfeature can minimize damage to the recess wall of the relief featureduring the laser-based treatment. Suitable geometric features for thispurpose include, but are not limited to an angle, a curve, or a grooveformed in the surface of the metal material proximate the recess wall ofthe relief feature. For example, an angle geometric feature may definean obtuse angle (e.g., angle from 110 degrees to 160 degrees) withrespect to the region of the recessed marking feature which is toundergo a laser-based treatment.

In aspects of the disclosure, a color feature produces a structuralcolor. Structural colors may result from a variety of effects includinginterference of light, diffraction of light, and combinations thereof.In embodiments, the color feature includes a metal oxide layerconfigured to produce a color through interference. The desired colormay be produced at a desired viewing angle. In additional embodiments,the color feature includes diffraction features configured to produce acolor through diffraction, such as laser induced periodic surfacestructures. In embodiments, the color feature does not include a paintor an ink.

The color of a color feature may be characterized using a color model.For example, in the hue-saturation-value (HSV) color model, the huerelates to the wavelength(s) of visible light observed when the colorfeature is viewed (e.g., blue or magenta) and the value relates to thelightness or darkness of a color and relates to the amount of lightreflected from the color feature. The saturation relates to theperceived colorfulness as judged in proportion to its brightness. Asanother example, coordinates in CIEL*a*b* (CIELAB) color space may beused to characterize the color, wherein L* represents brightness, a* theposition between red/magenta and green, and b* the position betweenyellow and blue. A broadband or semi-broadband illuminant may be used todetermine the color of the color feature. For example, a CIE illuminantmay be used.

Further, color(s) may be characterized in terms of perceived wavelengthsof visible light (e.g. from about 380 nm to about 750 nm). Chromaticcolors have a hue (such as predominantly red, blue, yellow or green). Aspectral color is present in the visible spectrum and is associated witha relatively narrow band of wavelengths. Non-spectral colors may includeachromatic colors (such as white, gray or black), colors that aremixtures of spectral colors (such as violet-red colors), colors that aremixtures of spectral colors with achromatic colors, and metallic colors.For example, a violet color may be associated with light having awavelength from about 380 nm to about 450 nm, a blue color may beassociated with light having a wavelength between about 450 nm to about495 nm, a cyan color may be associated with light having a wavelengthfrom about 490 nm to about 520 nm, a green color may be associated withlight having a wavelength between 495 nm and 570 nm, a yellow color maybe associated with light having a wavelength from about 570 nm to about590 nm, an orange color may be associated with light having a wavelengthfrom about 590 nm to 620 nm, and a red color may be associated withlight having a wavelength from about 620 nm to about 750 nm. Inaddition, a magenta color may be associated with light havingpredominantly red wavelengths and blue/violet wavelengths.

In additional embodiments, the spectral reflectance curve of a markingfeature may be used to describe its optical properties. The spectralreflectance curve may be obtained over the visible spectrum or over abroader range, such as from about 400 nm to about 1500 nm. In addition,the extent of specular reflection or directionality of the reflectancemay be measured.

A color feature having a metallic color may have a metallic luster. Forexample, a metallic color with a metallic luster may have a spectralreflectance curve with a relatively high reflectance over a relativelylarge portion of the visible spectrum and may have predominantlyspecular reflection. In embodiments, a color feature with a metallicluster has a spectral reflectance of at least 80%, at least 70%, atleast 60%, at least 50%, or at least 40% over at least a portion of thevisible spectrum. In embodiments, a metallic color may have a largelygray or “silvery” appearance when the spectral reflectivity issubstantially uniform across the visible spectrum. The laser coloringprocess may produce a structural color which modifies a gray or“silvery” appearance of a metal. For example, a laser coloring processmay change the spectral reflectance curve to decrease the reflectance inat least a portion of the blue and/or the green portion of the visiblespectrum, thereby producing an at least partially golden color feature.

In embodiments, a color feature may include an oxide layer which givesthe recessed marking feature a color (i.e., a marking color). The metaloxide may be a thermally grown metal oxide. In additional embodiments,the oxide layer may give the recessed marking feature more than onecolor. In some aspects, a first portion of the oxide layer may provide afirst marking color and a second portion of the oxide layer may providea second marking color. Alternately, the first portion of the oxidelayer may be referred to as a first oxide layer and the second portionof the oxide layer may be referred to as a second oxide layer.

In embodiments, a portion of the oxide may have a thickness or athickness range configured to produce a desired hue or combination ofhues, such as at a desired viewing angle. In additional aspects, thethickness of the oxide layer may vary such that the color feature blendsdifferent colors. For example, when the size of the recessed markingfeature is significantly greater than the spot size of the laser used toform the color feature, differences in heating of the metal substratemay produce some variation in the oxide layer thickness over therecessed marking feature.

A texture feature may include a texture formed into the external surfaceof the metal material. In embodiments, the texture feature includes asurface finish. The surface finish may define, at least in part, areflectance of the recessed marking feature. As an example, the surfacefinish may be characterized by the roughness of the external surface ofthe metal material. In additional embodiments, a texture feature mayinclude fine geometric features, such as hatching lines, formed into themetal material. The texture may be coated with a relatively thin oxidelayer formed during the texturing process. In embodiments, therelatively thin oxide layer may produce little, if any, color effect andmay have a thickness less than 5 nm, less than 3 nm, or less than 2 nm.

In embodiments, the laser-formed relief feature extends through amultilayer coating. For example, a coating layer may comprise a firstlayer disposed over the metal material and a second layer disposed overthe first layer. In further aspects, the coating layer consists of orconsists essentially of the first layer and the second layer. The firstcoating layer may comprise pigment particles and a binder. The pigmentparticles may be inorganic pigment particles, such as metal oxideparticles or carbon particles. In some aspects of the disclosure, theinorganic pigment particles give the first coating layer a white coloror a black color. The binder may be a polymer or resin binder, such asan acrylate or an epoxy binder. The pigment particles may be dispersedwithin the binder.

The second coating layer may comprise a transparent polymer. Thetransparent polymer may have a hardness and/or an abrasion resistancegreater than that of the first coating layer. For example, the secondcoating layer may comprise an acrylate polymer or an epoxy polymer. Thesecond coating layer may also comprise filler materials, such asnanoscale inorganic or diamond materials. By the way of example, themultilayer coating may have a thickness less than 1 mm, such as fromabout 50 μm to about 500 μm.

In additional aspects, the marking further comprises other features. Inembodiments, a laser-formed color feature may be formed in a layer ofthe coating. For example, exposure of pigment particles in the firstcoating to a laser beam may induce a color change in the pigmentparticles which can be used to form a marking. As an additional example,exposure of titanium dioxide particles in the first coating layer to thelaser beam can produce a darker color feature within the coating.

These and other embodiments are discussed below with reference to FIGS.1A-16. However, those skilled in the art will readily appreciate thatthe detailed description given herein with respect to these figures isfor explanatory purposes only and should not be construed as limiting.

FIG. 1A depicts a simplified example of an article. In some embodiments,the article 100 is an electronic device incorporating one or moreelectronic components. The article 100 may also be a component of anelectronic device including, for example, a housing, enclosure, or coverof an electronic device. The electronic device may be a portableelectronic device or other suitable electronic device. For example, theportable electronic device may be a laptop computer or a tablet. Asadditional examples, the portable electronic device may be awrist-watch, a media player, a mobile phone, a camera, a headphonedevice, an earpiece device, a remote control, an identifier (e.g., acard), or other electronic device.

In additional aspects of the disclosure, the article 100 may include adata bearing record, but need not incorporate an electronic component.As examples, the article 100 may have optical features and/or magneticfeatures which are capable of storing data and which are readable by acomponent of a data processing system. The article 100 may be portable.As example, the article 100 may be part of a laptop computer, a tablet,a wrist-watch, a media player, a mobile phone, a camera, a headphonedevice, an earpiece device, a remote control or may be an identifier(e.g., a card), or other such article.

As shown in FIG. 1A, the article 100 has an exterior surface 102 and amarking 120 has been formed along exterior surface 102. The location ofthe marking is not limited, and marking 120 may be formed on theexterior surface 106, the exterior surface 104, and/or the exteriorsurface 102 of the article 100. As examples, the exterior surface 102may be a front or a back surface of the device and the exterior surface104 may be a side surface of the device. As shown, the article 100includes a coating 130 which defines at least a portion of exteriorsurface 102. The coating 130 may be formed along an exterior surface 112of the metal substrate 140, as shown in FIG. 1D.

The article 100 further includes a device component 110. The devicecomponent 110, alone or in combination with other device components, maydefine an internal volume configured to receive one or more internalcomponents of the article 100. For example, the device component 110 maybe a component of a housing, enclosure, or cover for the article 100.The internal components of the article 100 may include variouselectronic components. For example, the electronic components mayinclude one or more of a processor, control circuitry, a sensor, memory,and a battery. An example electronic device is described below withrespect to FIG. 16 and the description provided there is generallyapplicable to articles as described herein.

As shown in FIG. 1A, the marking 120 further includes a first relieffeature 150 and a second relief feature 160. The first relief feature150 includes a perimeter 152 at the exterior surface 102 of the article100. The second relief feature 160 includes an interior perimeter 161and an exterior perimeter 162 at exterior surface 102; the interiorperimeter 161 forms an outline around a portion of the coating 130. Thevisual appearance of the first relief feature 150 and the second relieffeature 160 may differ from each other or may be the same. The visualappearance of each of the first relief feature 150 and the second relieffeature 160 differs from that of the coating 130. For example, the firstrelief feature 150 and the second relief feature 160 may be visuallydistinct from a portion of the coating layer adjacent to thelaser-formed relief feature. For example, an adjacent portion of thecoating may include an exterior surface of the coating layer and mayform a perimeter around the relief feature.

FIG. 1B shows an enlarged top view of the relief feature 150 of FIG. 1A(Detail 1-1). As shown in FIG. 1B, the relief feature 150 comprises arecessed marking feature 156. The relief feature 150 also comprises aperimeter 152 defined by the exterior surface of the coating 130. Therecessed marking feature 156 may have a visual appearance different fromthat of the coating 130 so that it is visually distinct from an adjacentportion of the coating (e.g., the coating adjacent perimeter 152). Insome embodiments, the recessed marking feature may have at least onedimension, such as a width, which is micro-scale (having a dimensiongreater than or equal to 1 micron and less than 1 millimeter). Inadditional embodiments, the recessed marking feature may have at leastone dimension, such as a width, which is milli-scale (having a dimensiongreater than or equal to 1 millimeter and less than 1 centimeter).

FIG. 1C shows an enlarged top view of the relief feature 160 of FIG. 1A(Detail 2-2). As shown in FIG. 1C, the relief feature 160 comprises arecessed marking feature 166. The recessed marking feature 166 may havea visual appearance different from that of the coating 130. The relieffeature 160 also comprises an interior perimeter 161 and an exteriorperimeter 162 defined by the exterior surface of the coating 130.

FIG. 1D is an example cross-sectional view of the relief feature 160 ofFIG. 1C. FIG. 1D provides an example of a fine marking which can beproduced using a laser-based technique to remove some of the coating 130and expose some of a metal substrate 140. As shown, removal of some ofthe coating does not significantly distort the remainder of the coatingor the underlying metal substrate. Although the exposed metal substrate140 is depicted as being flat, this is not limiting, as described belowwith respect to the examples of FIGS. 1E, 2-5, 6B, 7-9, and 10B. Inadditional examples, the metal substrate may be referred to as a metalmaterial. Further, a metal oxide layer may be formed on the exposedmetal substrate as described below with respect to FIGS. 6A-9.

The relief feature 160 comprises a recessed marking feature 166, whichis recessed with respect to the exterior surface 102 of the article 100.The recessed feature 166 is positioned below a recess 163 in the coating130 and has a width W. The coating 130 around the recess 163 definesrecess walls 164 (side walls) of the relief feature 160. Although therecess walls 164 are shown as forming an angle of about 90° with respectto surface 112, this is not limiting, as shown with respect to FIG. 1E.An exterior surface of the coating 130 defines at least a portion of theexterior surface 102 of the article 100.

As shown in FIG. 1D, the coating 130 is formed along an exterior surface112 of the metal substrate 140 and the recessed marking feature 166 isformed along an exterior surface 114 of the metal substrate 140. Theexterior surface 112 may be a first portion and the exterior surface 114may be a second portion of the exterior or outer surface of the metalsubstrate 140. The exterior surface 114 is not required to be at thesame height as the exterior surface 112. For example, laser-basedtreatment of exterior surface 114 may cause the exterior surface 114 tobe recessed with respect to the exterior surface 112. In someembodiments, the exterior surface 114 is recessed by 5 μm or less, 3 μmor less, 2 μm or less, or 1 μm, or less with respect to the exteriorsurface 112. As for the exterior surface 102, the exterior surface 114may be a front, a back, or a recess wall of the metal substrate.

The exterior surface 114 may have a texture which gives the recessedmarking feature a visual attribute. For example, the exterior surface114 may have a surface finish with a roughness corresponding to that ofa polished surface. The roughness of the exterior surface 114 may befrom about 1 μm to about 5 μm. In additional example, the roughness ofthe exterior surface 114 may be greater than 5 μm, or greater than 10μm. One measure of surface roughness is the parameter Ra which is ameasure of the amplitude of the roughness profile (arithmetic averagevalue of roughness determined from deviations about a center line).Another parameter is Sm, which is the mean spacing between peaks in theroughness profile. Reflectance may also be used as a measure of surfaceroughness. The foregoing discussion of texture and surface finish is notlimited to the example of FIG. 1D, but applies more generally to texturefeatures of the present disclosure.

Further, the exterior surface 114 may include an oxide layer which givesthe recessed marking feature a marking color. The metal oxide may be athermally grown metal oxide. For example, the metal oxide layer may bethermally grown on a metal material by laser heating of the substrate.Suitable metal materials include, but are not limited to, titaniumalloys, steels, or zirconium based, titanium-based, or iron-based bulksolidifying alloy substrates. In some embodiments, the metal material ispredominantly crystalline and may have percentage of crystallinephase(s) greater than 50%, 60%, 70%, 80%, or 90%. In some embodiments,the thermally grown metal oxide may have a porosity less than that of ananodically grown porous metal oxide. In embodiments, the metal oxide maycomprise a titanium oxide, an iron oxide, a chromium oxide, a zirconiumoxide or combinations thereof.

The thickness of a metal oxide layer can affect the color of therecessed marking feature in several ways. For example, a metal oxidelayer may display a color as a result of interference of light reflectedfrom the metal oxide and the underlying metallic substrate. Typicallythe interference color displayed depends upon the thickness of the metaloxide. A metal oxide having a thickness too great to displayinterference colors may appear dark. When the metal oxide is very thin(or is not present), the recessed marking feature may appear bright ormetallic. A variety of colors may be obtained, including, but notlimited to, blue, purple, pink, red, orange, yellow, gold, brown, andgreen. Suitable thicknesses of the metal oxide layer to achieve a colorfrom light interference may depend on the composition and crystallinityof the layer as well as the desired color to be achieved. As an example,a thickness of the metal oxide layer may be from 50 nm to 500 nm toobtain a color through interference of light. The foregoing discussionof color features including a metal oxide layer is not limited to theexample of FIG. 1D, but applies more generally to color features of thepresent disclosure.

The coating 130 may be a multilayer coating. As shown in FIG. 1D, thecoating 130 includes a first coating layer 134 having a thickness T₁ anda second coating layer 136 having a thickness T₂. The thickness of thefirst coating layer may be greater than that of the second coatinglayer. In some embodiments the combined thickness of the coating layersis from 50 μm to 500 μm or from 100 μm to 300 μm. The first coatinglayer 134 is disposed over the exterior surface 112 of the metalsubstrate 140 and, as shown in FIG. 1D, may contact the exterior surface112 at an interface between the coating 130 and the metal substrate 140.The second coating layer 136 is disposed over the first coating layer134. In some instances, the first coating layer 134 may be positionedover or may include a primer layer that coats or is positioned along asurface of the metal substrate 140. The primer may include a polymermaterial including, for example, a urethane, acrylate or polymermaterial that facilitates adhesion to the metal substrate 140. Forpurposes of this description, the first coating layer 134 may include asub layer or layers of primers or other materials. That is, the firstcoating layer 134 is not necessarily homogenous or uniform throughoutthe thickness of the layer.

In embodiments, the first coating layer 134 comprises pigment particlesand a polymer binder. As an example, the pigment particles may beinorganic pigment particles. Inorganic pigments include, but are notlimited to, metal oxides such as titanium oxides (TiO₂, Ti₂O₃), zincoxides (ZnO), manganese dioxide (MnO₂), and iron oxides (Fe₃O₄). Theparticles may have a size range of 0.1 μm to 10 μm or 0.1 μm to 1 μm.Suitable polymers for the binder include, but are not limited to, singleurethane polymers, multi urethane polymers, polyurethane, acrylatepolymers, and epoxy polymers. The first coating layer may furthercomprise other additives in addition to the pigment. When the firstcoating layer 134 includes a sub layer of a primer, the first coatinglayer 134 may also include another sub layer comprising the pigmentparticles and the polymer binder.

In embodiments, the second coating layer 136 is transparent andcomprises a transparent polymer. The transparent polymer may have ahardness and/or an abrasion resistance greater than that of the firstcoating layer. For example, the second coating layer may comprise anacrylate polymer or an epoxy polymer. The second coating may be a UVcurable acrylic or other type of optically cured polymer. The secondcoating layer may also comprise filler materials, such as nanoscaleinorganic or diamond materials. Nanoscale filler materials may have adiameter less than 100 nm or less than 50 nm. The second coating layermay also include various fillers including, for example, wax fillers,fluoropolymers, silica fillers, fluorosurfactant surface modifiers, andother materials. The second coating layer 136 may be treated to providea particular surface texture or hand feel. In some instances, the secondcoating may provide a ceramic-like feel to the touch. For example, thesecond coating layer may include a UV curable acrylic having wax andsilica fillers sufficient to simulate a smooth ceramic-like frictionbetween the surface and the skin of a user's finger. The foregoingdiscussion of the first and second coating layers is not limited to theexample of FIG. 1D, but applies more generally to multilayer coatings ofthe present disclosure.

FIG. 1E is another example cross-sectional view of the relief feature160 of FIG. 1B. FIG. 1E provides another example of a fine marking whichcan be produced using a laser-based technique to remove some of thecoating 130 and expose some of the metal substrate 140. As shown,removal of some of the coating does not significantly distort theremainder of the coating or the underlying metal substrate. Although theexposed metal substrate 140 is depicted as being concave, this is notlimiting. Further, a metal oxide layer may be formed on the exposedmetal substrate as described below with respect to FIGS. 6A-9.

The relief feature 160 comprises a recessed marking feature 166, whichis recessed with respect to the exterior surface 102 of the article 100.The recessed feature 166 is positioned below a recess 163 formed atleast in part in the coating 130 and the recessed feature 166 has awidth W. The coating 130 around the recess 163 defines recess walls 164(side walls) of the relief feature 160. Although recess walls 164 areshown as having an oblique angle with respect to surface 112, this isnot limiting. An exterior surface of the coating defines at least aportion of the exterior surface 102 of the article 100.

FIGS. 2-9 and 10B illustrate schematic cross-sectional views of markingsalong exterior surfaces of example articles. By the way of example, theexterior surfaces of the articles of FIGS. 2-9 and 10B may be frontsurfaces of the article. Alternately, the exterior surfaces of thearticles of FIGS. 2-9 and 10B may be a back surfaces or side surfaces ofthe article. In aspects of the disclosure, the articles of FIGS. 2-9 and10B are electronic devices.

FIG. 2 shows a schematic cross-sectional view of an example marking 220comprising a recessed marking feature 266 including a geometric feature272. As illustrated in FIG. 2, the geometric feature 272 is a grooveformed in the exterior surface 214 of a metal material 240, which mayalso be referred to as a metal substrate. As shown, the groove 272 isproximate the recess wall 264 of the relief feature 260. The groove mayhave a rounded cross-sectional shape. As an example, a width of thegroove may be about 10% or less of the width W of the recessed markingfeature.

As shown in FIG. 2, the device component 210 includes the marking 220along an exterior surface 202 of the article. The device component 210includes a coating 230 along an exterior surface 212 of the metalmaterial 240. The coating includes a first layer 234 and a second layer236. The marking 220 comprises a relief feature 260 including a recessedmarking feature 266 and recess wall 264. The recess wall 264 at leastpartially defines a recess 263.

FIG. 3 shows a schematic cross-sectional view of an example marking 320comprising a recessed marking feature 366 including multiple geometricfeatures 372. As shown in FIG. 3, the geometric features 372 are groovesformed in an exterior surface 314 of a metal material 340. Asillustrated, the grooves 372 have an angular cross-sectional shape andare arranged to form a pattern. As an example, a width of the groove maybe about 10% or less of the width W of the recessed marking feature.

As shown in FIG. 3, the device component 310 includes the marking 320along an exterior surface 302 of the article. The device component 310includes coating 330 along an exterior surface 312 of the metal material340. The coating includes a first layer 334 and a second layer 336. Themarking 320 comprises a relief feature 360 including recessed markingfeature 366 and recess wall 364. The recess wall 364 at least partiallydefines a recess 363.

FIG. 4 shows a schematic cross-sectional view of another example marking420 comprising a recessed marking feature 466 including a geometricfeature 472. As shown in FIG. 4, the geometric feature 472 is a channel(or groove) formed in an exterior surface 414 of a metal material 440and having an angular cross-sectional shape. The channel 472 may have awidth about equal to the width W of the recessed marking feature 466.For example, a width of the geometric feature may be from about 80% to100% of the width of the recessed marking feature 466. An angle θbetween walls 473 a and 473 b may be greater than about 45 degrees andless than 180 degrees or from about 60 degrees to about 120 degrees. Thewalls 473 a and 473 b may also be referred to as a pair of channel orgroove walls.

As shown in FIG. 4, a device component 410 includes the marking 420along an exterior surface 402 of the article. The device component 410includes a coating 430 along an exterior surface 412 of the metalmaterial 440. The coating 430 includes a first layer 434 and a secondlayer 436. The marking 420 comprises a relief feature 460 including therecessed marking feature 466 and a recess wall 464. Recess wall 464 atleast partially defines a recess 463.

FIG. 5 shows a schematic cross-sectional view of an additional examplemarking 520 comprising a recessed marking feature 566 including ageometric feature 572. As shown in FIG. 5, the geometric feature 572 isa channel formed in an exterior surface 514 of a metal material 540 andhaving a rounded cross-sectional shape. The rounded cross-sectionalshape may be described by a first radius of curvature R₁ proximate therecess wall 564 and a second radius of curvature R₂ at the bottom of thechannel. As shown, the second radius of curvature may have larger amagnitude than that of the first radius of curvature and may producecurvature of opposite direction or sign. The channel 572 may have awidth about equal to the width W of the recessed marking feature 566.For example, a width of the channel may be from about 80% to 100% of thewidth W of the recessed marking feature 566. An angle θ between walls573 a and 573 b may be greater than about 45 degrees and less than 180degrees or from about 60 degrees to about 120 degrees. The channel 572may have a depth D.

As shown in FIG. 5, a device component 510 includes the marking 520along an exterior surface 502 of the article. The device component 510includes a coating 530 along an exterior surface 512 of the metalmaterial 540. The coating includes a first layer 534 and a second layer536. The marking 520 comprises a relief feature 560 including therecessed marking feature 566 and the recess wall 564. The recess wall564 at least partially defines recess 563.

FIG. 6A shows a schematic cross-sectional view of an example marking 620comprising a recessed marking feature 666 including a metal oxide layer682 formed along an exterior surface 614 of a metal material 640. Asshown, the metal oxide layer 682 may have a thickness T and may extendacross a width about equal to the width W of the recessed markingfeature 666. As previously discussed, the thickness of the metal oxidelayer 682 may be configured to produce a structural color throughinterference.

As shown in FIG. 6A, the thickness of the metal oxide layer 682 issubstantially uniform. However, the illustration of FIG. 6A is notlimiting and the thickness of the metal oxide layer may vary across therecessed marking feature. In embodiments, an oxide layer of varyingthickness may be described by an average thickness or by a thicknessrange. In an embodiment, the extent of metal oxide thickness variation(e.g., the thickness range) may be small enough that the colors of therecessed marking feature are encompassed by single spectral color or hue(e.g., blue or green). In other embodiments, the recessed markingfeature may display multiple distinct spectral colors or hues or ablending of different colors. In some embodiments, the desired viewingangle is about normal to the recessed marking feature 666.

As shown in FIG. 6A, a device component 610 includes the marking 620along an exterior surface 602 of the article. A device component 610includes a coating 630 along an exterior surface 612 of metal material640. The coating 630 includes a first layer 634 and a second layer 636.The marking 620 comprises a relief feature 660 including the recessedmarking feature 666 and a recess wall 664. The recess wall 664 at leastpartially defines a recess 663. As shown in FIG. 6A the exterior surface614 under the metal oxide layer 682 may be recessed with respect toexterior surface 612 under the coating 630 due to growth of the metaloxide layer 682 into the metal material 640.

FIG. 6B shows a schematic cross-sectional view of an example marking 620comprising a recessed marking feature 666 including a metal oxide layer682 formed along an exterior surface 614 of a metal material 640. Asshown, the metal material 640 defines a channel 672 including walls 673a, 673 b. The metal oxide layer 682 is positioned within the channel,has a thickness T, and extends across a width W_(O) less than the widthW of the recessed marking feature 666. As previously discussed, thethickness of the metal oxide layer 682 may have a thickness or athickness range configured to produce a desired hue or combination ofhues, such as at a desired viewing angle. In embodiments, the desiredviewing angle is about normal to the recessed marking feature 666.

In addition, the walls 673 a, 673 b may each be viewed as angledgeometric features which form a complete or partial perimeter around themetal oxide layer 682. The walls 673 a, 673 b may define an obtuse angle(e.g., angle from 110 degrees to 160 degrees) with respect to a plane ofthe metal oxide layer 682 or the exterior surface 602. Similarly, acomplementary angle between walls 673 a, 673 b and the recess wall 664may be an acute angle.

As shown in FIG. 6B, a device component 610 includes the marking 620along an exterior surface 602 of the article. The device component 610includes a coating 630 along an exterior surface 612 of the metalmaterial 640. The coating includes a first layer 634 and a second layer636. The marking 620 comprises a relief feature 660 including therecessed marking feature 666 and a recess wall 664. The recess wall 664at least partially defines a recess 663. As shown in FIG. 6B theexterior surface 614 under the metal oxide layer 682 is recessed withrespect to exterior surface 612 under the coating 630.

In additional embodiments, one or more geometric features may be formedin the metal oxide layer. The geometric feature may be any geometricfeature described herein. The multiple geometric features may form apattern. For example, multiple aligned grooves may form a hatching.

In additional aspects, a marking may include a recessed marking featureincluding a first color defined, in part, by a first metal oxidethickness and a second color defined, in part, by a second metal oxidethickness. FIG. 7 shows a schematic cross-sectional view of an examplemarking 720 comprising a recessed marking feature 766 including a metaloxide layer 782 a, 782 b and a geometric feature 772 a, 772 b. As shown,the metal oxide layer 782 may be formed along an exterior surface 714 ofa metal material 740 and may include a first portion 782 a having afirst thickness T₁ and a second portion 782 b having a second thicknessT₂. The first portion of the metal oxide layer may provide a first colorand the second portion of the metal oxide layer may provide a secondcolor. The first color and/or the second color may be defined, in part,by light interference. As previously discussed, the thickness of thefirst portion 782 a and the second portion 782 b of the oxide layer mayhave a thickness or a thickness range configured to produce a desiredhue or combination of hues, such as at a desired viewing angle. Inembodiments, the desired viewing angle is about normal to the recessedmarking feature 766.

Recessed marking features including a first metal oxide thickness and asecond metal oxide thickness may be obtained by various methods. Thesecond portion of the oxide layer may be grown to a different thicknessthan the first portion of the oxide layer. Further, laser ablation maybe used to reduce the thickness of the oxide layer to the first and/orthe second thickness. Alternately, the first portion of the oxide layermay be referred to as a first oxide layer and the second portion of theoxide layer may be referred to as a second oxide layer.

As shown in FIG. 7, the geometric feature 772 a, 772 b is a grooveformed in an exterior surface 714 of the metal material 740 proximatethe recess wall 764 of the relief feature. The geometric feature 772 a,772 b is also shown as having a rounded cross-sectional shape. FIG. 7shows the groove as having two portions 772 a, 772 b; the groove shownin FIG. 7 may form a full or partial loop. As shown, the metal oxidelayer 782 is at least partially inward from portions 772 a, 772 b of thegroove. The metal oxide layer 782 extends across a width about equal toa distance between portions 772 a, 772 b of the groove.

As shown in FIG. 7, a device component 710 includes the marking 720along an exterior surface 702 of the article. The device component 710includes a coating 730 along an exterior surface 712 of the metalmaterial 740. The coating includes a first layer 734 and a second layer736. The marking 720 comprises a relief feature 760 including therecessed marking feature 766 and a recess wall 764. Recess wall 764 atleast partially defines a recess 763. When the metal oxide layer 782grows upward from the level of the exterior surface 712, a portion ofthe recess 763 may be to the side of, rather than above, the recessedmarking feature 766.

FIG. 8 shows a schematic cross-sectional view of an additional examplemarking 820. Marking 820 includes a relief feature 860 comprising ageometric feature 872 and a recessed marking feature 866 including ametal oxide layer 882. As shown, the metal oxide layer 882 is formedover the geometric feature 872 and has a thickness T. As previouslydiscussed, the metal oxide layer 882 may have a thickness or a thicknessrange configured to produce a desired hue or combination of hues, suchas at a desired viewing angle. In embodiments, the desired viewing angleis about normal to the coating 830.

As shown in FIG. 8, the geometric feature 872 may be a channel formed inan exterior surface 814 of the metal material 840. The channel 872 mayhave a cross-sectional shape which defines walls 873 a and 873 b. Anangle between the walls 873 a and 873 b may be greater than about 45degrees and less than 180 degrees or from about 60 degrees to about 120degrees. The channel feature 872 may have a width about equal to thewidth W of the recessed marking feature 866, such as from about 80% to100% of the width of the recessed marking feature 866.

The metal oxide layer 882 is formed along an exterior surface 814 ofmetal material 840 and along at least a portion of the exterior surfaceof channel 872. As shown, the metal oxide layer 882 extends across awidth about equal to the width W of the recessed marking feature 866. Anexterior surface of the oxide layer 882 on wall 873 a may form an anglewith an exterior surface of the oxide layer 882 on wall 873 b due to theunderlying channel geometry. This angle may be greater than about 45degrees and less than 180 degrees or from about 60 degrees to about 120degrees.

As shown in FIG. 8, a device component 810 includes a marking 820 alongan exterior surface 802 of the article. The device component 810includes a coating 830 along an exterior surface 812 of a metal material840. The coating 830 includes a first layer 834 and a second layer 836.The marking 820 comprises a relief feature 860 including the recessedmarking feature 866 and a recess wall 864.

In further aspects, a marking may include a recessed marking featureincluding a first color defined, in part, by a first metal oxidethickness along a first wall of a groove or channel and a second colordefined, in part, by a second metal oxide thickness along a second wallof the groove or channel. An apparent color of the recessed markingfeature may be due to a combined effect of the first color and thesecond color. The apparent color of such a recessed marking feature maydepend upon viewing angle. For example, from some viewing anglesapproximately equal amounts of the first wall and the second wall may bevisible, and both the first and the second colors may be visible asdistinct colors. From other viewing angles, the visible amount of thefirst wall may be significantly less than that of the second wall, andthe color of the recessed marking feature may be dominated by the firstcolor or may appear to have the first color (and vice versa). Theapparent color of the recessed marking feature may therefore appear toshift as the viewing angle is changed.

FIG. 9 shows a schematic cross-sectional view of an additional examplemarking 920. The marking 920 includes a relief feature 960 comprising ageometric feature 972 and a recessed marking feature 966. As shown inFIG. 9, the recessed marking feature 966 comprises a metal oxide layerincluding a first portion 982 a having a first thickness T₁ and a secondportion 982 b having a second thickness T₂. As shown, the firstthickness is less than the second thickness. Metal oxide portions 982 a,982 b are formed along an exterior surface 914 of a metal material 940and along at least a portion of the exterior surface of the geometricfeature 972. As previously discussed, the thickness of the first portion982 a and the second portion 982 b of the oxide layer may each have athickness or a thickness range configured to produce a desired hue orcombination of hues, such as at a desired viewing angle. In embodiments,the desired viewing angle is about normal to the coating 930.

As shown in FIG. 9, the geometric feature 972 may be a groove formed inthe exterior surface 914 of the metal material 940. The groove 972 mayhave a cross-sectional shape which defines walls 973 a and 973 b. Anangle between the walls 973 a and 973 b may be greater than about 45degrees and less than 180 degrees or from about 60 degrees to about 120degrees. The groove 972 may have a width about equal to the width W ofthe recessed marking feature 966, such as from about 80% to 100% of thewidth of the recessed marking feature 966.

As shown, the metal oxide layer extends across a width about equal tothe width W of the recessed marking feature 966. An exterior surface ofthe oxide layer on wall 973 a may form an angle with an exterior surfaceof the oxide layer on wall 973 b due to the underlying groove geometry.This angle may be greater than about 45 degrees and less than 180degrees or from about 60 degrees to about 120 degrees.

As shown in FIG. 9, a device component 910 includes the marking 920along an exterior surface 902 of the article. The device component 910includes a coating 930 along an exterior surface 912 of the metalmaterial 940. The coating includes a first layer 934 and a second layer936. The marking 920 comprises a relief feature 960 including therecessed marking feature 966 and a recess wall 964. Recess wall 964 atleast partially defines a recess 963.

In additional aspects, a marking includes at least two recessed markingfeatures. For example, a first recessed marking feature may define afirst region which is visually distinct from the coating. Each of thefirst and the second recessed marking feature may include a geometricfeature, a color feature, a texture feature, or a combination thereof.The second recessed marking feature may have a visual attributedifferent from the first recessed marking feature. The second recessedmarking feature may at least partially surround the first recessedmarking feature, or vice versa. FIGS. 10A, 10B, 11A, 11B, and 11Cillustrate non-limiting examples of markings including two recessedmarking features.

The first and the second recessed marking features may encompass equalor unequal portions of the marking. The visual attribute(s) of thelarger of the first recessed marking feature and the second recessedmarking feature may dominate the appearance of the marking. For example,if the second recessed marking feature is thin relative to the firstrecessed marking feature, the attributes of the first recessed markingfeature may largely determine the appearance of the marking. Forexample, the second recessed marking feature may have a width less thanthat of the first recessed marking feature and may form a complete orpartial perimeter around the first recessed marking feature.

FIG. 10A shows an enlarged view of an additional example marking 1020 ofFIG. 1A showing a top view of a relief feature 1050. As shown in FIG.10A, the relief feature 1050 comprises recessed marking features 1056 a,1056 b. A shown, the recessed marking feature 1056 b includes a texturefeature and is visually distinct from a coating 1030. The relief feature1050 also includes a recessed marking feature 1056 a which defines aperimeter at least partially surrounding the recessed marking feature1056 b. The relief feature 1050 also includes a perimeter 1052 aroundrecessed marking feature 1056 and defined by the coating 1030.

FIG. 10B shows a schematic cross-sectional view of the marking 1020 ofFIG. 10A.

As illustrated in FIG. 10B, the marking 1020 includes a relief feature1050. A recessed marking feature 1056 a of the relief feature 1050includes a channel 1072 formed in an exterior surface 1014 a of a metalmaterial 1040. As shown, the channel 1072 is proximate a recess wall1054 of the relief feature 1050.

As shown in FIG. 10B, the marking 1020 also includes a recessed markingfeature 1056 b. The recessed marking feature 1056 b includes a surfaceroughness formed in exterior surface 1014 b of the metal material. Therecessed marking feature 1056 b may be wider than the recessed markingfeature 1056 b.

As shown in FIG. 10B, a device component 1010 includes the marking 1020along an exterior surface 1002 of the article. The device component 1010includes a coating 1030 along an exterior surface 1012 of the metalmaterial 1040. The coating includes a first layer 1034 having athickness T₁ and a second layer 1036 having a thickness T₂. The relieffeature 1050 includes a recess wall 1054. The recess wall 1054 at leastpartially defines a recess 1053.

FIG. 11A shows an enlarged view of a further example marking 1120 ofFIG. 1A showing a top view of a relief feature 1150. As shown in FIG.11A, the relief feature 1150 comprises recessed marking features 1156 a,1156 b. A shown, the recessed marking feature 1156 b includes multiplegrooves arranged in a hatching pattern and is visually distinct from acoating 1130. The relief feature 1150 also includes a recessed markingfeature 1156 a which defines a perimeter at least partially surroundingthe recessed marking feature 1156 b. The relief feature 1150 alsoincludes a perimeter 1152 around the recessed marking feature 1156 a anddefined by the coating 1130.

As shown in FIG. 11B, relief feature 1150 comprises recessed markingfeature 1150. As shown in FIG. 11B, relief feature 1150 comprisesrecessed marking features 1156 a, 1156 b. A shown, recessed markingfeature 1156 b includes multiple grooves arranged in cross-hatchingpattern and is visually distinct from coating 1130. Relief feature 1150also includes recessed marking feature 1156 a which defines a perimeterat least partially surrounding recessed marking feature 1156 b. Therelief feature 1150 also includes a perimeter 1152 around the recessedmarking feature 1156 a and defined by the coating 1130.

FIG. 11C shows an enlarged view of another marking of FIG. 1A showing atop view of a relief feature 1150. As shown in FIG. 11B, the relieffeature 1150 comprises recessed marking features 1156 a, 1156 b.Recessed marking feature 1156 b includes multiple circular geometricfeatures 1172 and is visually distinct from coating 1130. Relief feature1156 also includes recessed marking feature 1156 a which defines aperimeter at least partially surrounding recessed marking feature 1156b. The relief feature 1150 also includes a perimeter 1152 around therecessed marking feature 1156 a and defined by the coating 1130.

The current description also encompasses processes for forming a markingalong an exterior surface of an article. The article may be anelectronic device. The processes may be performed on an articlecomprising a device component. The device component may comprise asubstrate comprising a metal material and may further comprise a coatingdisposed over an exterior surface of the substrate. The coating may be amultilayer coating as described herein comprising a first layer disposedover the metal material and a second layer disposed over the firstlayer. The electronic device may include markings formed along anexternal surface of the device component, within the coating, or acombination thereof.

In embodiments, the processes for forming a marking along an externalsurface of the device component comprise laser ablating the coating inthe marking area to expose a metal portion of the device component andlaser modifying the metal portion to create a recessed marking feature.The operation of laser modifying the metal portion may comprise at leastone of laser texturing and laser coloring the metal portion. Inaddition, the operation of laser modifying the metal portion maycomprise laser shaping the metal portion to form a geometric feature.For example, the metal portion may be laser shaped through ablation toform a depression; the depression may then be laser textured and/orlaser colored. The metal portion may be laser textured through ablation,partial melting, or combinations thereof. In embodiments, the metalportion may be laser colored through annealing without substantialablation or melting.

FIG. 12 illustrates a flowchart of an example process 1200 for forming amarking along an exterior surface of an article. Process 1200 may beused to form a relief feature having a recessed marking feature. Therecessed marking feature may be formed along an exterior surface ofsubstrate comprising a metal material; a texture feature and/orgeometric feature may be formed in a metal portion of the substrate toproduce a visual effect. As examples, process 1200 may be used to formthe recessed marking features of FIGS. 1D, 1E, and 2-5 along an exteriorsurface of the metal portion. As used herein, a metal portion mayinclude a metal alloy portion.

Operation 1210 comprises laser ablating the coating in a marking area ofthe article. The marking area is along an exterior surface of thearticle defined by an exterior surface of the coating. As an example,operation 1210 comprises removing, using a first laser, a first portionof the coating which is located in the marking area. The operation oflaser ablating the coating in the marking area may use a first laser.For example, the first laser may be a femtosecond laser producing pulseshaving an effective pulse duration in the femtosecond range. The firstlaser may produce a wavelength in the ultraviolet range (e.g., having awavelength from about 200 nm to about 400 nm). Alternately, the firstlaser may produce a wavelength in the infrared range (e.g., having awavelength from about 1 μm to about 5 μm). The first laser may beoperated in a vector mode, a raster mode, or a combination thereof.

For example, a vector mode may be used to laser ablate an outline in thefirst portion of the coating and a raster mode may be used to laserablate coating within the outline, thereby laser ablating a remainder ofthe first portion of the coating. In some embodiments, the wavelengthused to ablate an outline in the first portion of the coating may bedifferent than the wavelength used to remove a remainder of the firstportion of the coating within the outline.

By the way of example, a laser used to ablate an outline in the firstportion of the coating may have a pulse duration from about 200 fs toabout 800 fs, an average power from about 0.5 W to about 15 W or about 1W to about 10 W. The repetition rate may be from about 10 kHz to 750kHz, from about 10 kHz to about 500 kHz, or from about 10 kHz to about100 kHz. In some embodiments, the laser may be operated in burst mode,with each burst including multiple pulses. In embodiments, the number ofpulses in the burst may be from 5 to 25. The scan speed may be fromabout 1 mm/sec to about 50 mm/sec. The laser used to form the outlinemay be operated in vector mode.

In addition, a laser operated to remove a remainder of the first portionof the coating may have an average power, a repetition rate and/or ascan speed higher than that used to form the outline. For example, thepulse duration may be from about 200 fs to about 800 fs, the averagepower may be from about 0.5 W to about 15 W or about 1 W to about 10 W.The repetition rate may be from about 50 kHz to about 1000 kHz or fromabout 200 kHz to about 750 kHz. In some embodiments, the laser may beoperated in burst mode, with each burst including multiple pulses. Inembodiments, the number of pulses in the burst may be from 5 to 25. Thescan speed may be from about 100 mm/sec to about 1000 mm/sec, the hatchdistance from about 5 μm to about 30 μm, and the number of passes from 1to 8. The spot size may be from 10 μm to 50 μm. The laser used to removethe remainder of the first portion of the coating may be operated inraster mode. In embodiments, the same laser may be used to form theoutline as to remove the remainder of the first portion of the coatingor different lasers may be used.

As explained in further detail with respect to FIGS. 13A and 13B, theoperation of removing the first portion of the coating using the firstlaser may form a recess extending through the coating. A second portion(remainder portion) of the coating surrounds the recess and defines arecess wall. The operation of removing the first portion of the coatingalso exposes a metal portion of the substrate. The exposed metal portionis under the recess. The exposed metal portion may alternately bereferred to as a metal portion.

In embodiments, the laser(s) used in operation 1210 may be operatedunder conditions which minimize damage to the coating defining andadjacent to the recess wall. The coating may be a multilayer coatingincluding a first layer and a second layer as previously described. Inan example, few, if any, visually observable cracks are produced in thesecond layer and/or the recess wall during operation 1210. In someembodiments, heating of the second layer during operation 1210 may helpprevent cracking of this layer.

As previously discussed, the process of forming a marking along anexterior surface of an article may comprise modifying the exposed metalportion, using a laser, to create a recessed marking feature of therelief feature. The operation 1220 of the process 1200 comprises lasertexturing within the marking area of the article. The operation of lasertexturing may form a texture feature, a geometric feature, or acombination thereof into the exposed metal portion. In some embodiments,the operation of laser texturing may also affect the color of themarking feature. For example, the surface roughness of the markingfeature may affect the brightness or darkness of the marking feature.

The operation of laser texturing may use a second laser. For example,the second laser may be a femtosecond laser producing pulses having aneffective pulse duration in the femtosecond range. For example, thefemtosecond laser may be used to form one or more geometric featuresinto the exposed metal portion (e.g., hatching as shown in FIGS.11A-11B). The femtosecond laser may produce a wavelength in the infraredrange. The second laser may be operated in a vector mode, a raster mode,or a combination thereof. The pulse duration may be from 200 fs to 800fs, the average power may be from about 0.01 W to about 15 W, from about1 W to about 15 W, or from about 0.01 W to about 5 W, and the repetitionrate may be from about 50 kHz to about 750 kHz or from about 50 kHz toabout 300 kHz. In some embodiments, the laser may be operated in burstmode, with each burst including multiple pulses. In embodiments, thenumber of pulses in the burst may be from 5 to 25. The scan speed may befrom about 750 mm/sec to about 1500 mm/sec, the hatch distance up to 50μm, and the number of passes from 1 to 25. The spot size may be fromabout 10 μm to about 50 μm. Some geometric features, such as those shownin FIGS. 7 and 8, may be formed using multiple passes of the secondlaser. In some embodiments, the operation of laser texturing includesmultiple laser texturing operations at different laser operatingconditions.

In some embodiments, a nanosecond laser producing pulses having aneffective pulse duration in the nanosecond range may be used in additionto or as an alternate to a femtosecond laser. For example, thenanosecond laser may be used to polish the exposed metal portion,thereby modifying the roughness of the exposed metal portion. The lasermay produce a wavelength in the near infrared range. The pulse durationmay be from about 2 ns to about 300 ns, the average power may be fromabout 0.01 W to about 15 W, from about 0.01 W to about 5 W, or fromabout 1 W to about 10 W. The repetition rate may be from about 50 kHz toabout 400 kHz. In some embodiments, the laser may be operated in burstmode, with each burst including multiple pulses. In embodiments, thenumber of pulses in the burst may be from 5 to 25. The scan speed may befrom about 200 mm/sec to about 2000 mm/sec, the hatch distance fromabout 5 μm to about 30 μm, and the number of passes from 1 to 10. Thespot size may be from about 10 μm to about 50 μm.

Process 1200 may optionally include operation 1230 of laser coloring themarking area. Operation 1230 may occur as part of an annealingoperation. As an example, operation 1230 comprises modifying the exposedmetal portion of the substrate, using a third laser, to create a colorfeature along an exterior surface of the metal portion. In embodiments,the operation of laser coloring the marking area produces a structuralcolor. As previously discussed, structural colors may result from avariety of effects including interference of light, diffraction oflight, and combinations thereof.

In embodiments, operation 1230 comprises thermally growing a metal oxidelayer in the marking area of the article. The metal oxide layer mayprovide a structural color through interference of light. As an example,operation 1230 comprises modifying the exposed metal portion of thesubstrate, using a third laser, to create a metal oxide layer along anexterior surface of the metal portion. In some embodiments, theoperation of thermally growing the oxide layer includes multiple oxidegrowth operations at different laser operation conditions, for exampleat different locations on the exterior surface of the metal material.

In additional embodiments, operation 1230 comprises forming diffractionfeatures along the exterior of the metal portion which provide astructural color through diffraction of light. In further embodiments,operation 1230 gives a desired metallic color to the marking area. Themetallic color may be characterized by a reflectivity as well as acolor. In some embodiments, a steel, titanium, or titanium alloysubstrate may be given the appearance of a metal such as silver,palladium, platinum, or gold. In further embodiments, a metallic colormay be obtaining by limiting the extent of annealing of the metalportion, such as by using a relatively low power and/or a relativelyhigh scan speed.

In embodiments, operation 1230 may use a nanosecond laser producingpulses having an effective pulse duration in the nanosecond range. Inembodiments, the nanosecond laser is used to form a metal oxide layer.The nanosecond laser may produce a wavelength in the near infraredrange. The pulse duration may be from about 2 ns to about 500 ns, theaverage power may be from about 1 W to about 15 W, and the repetitionrate may be from about 100 kHz to about 750 kHz or from about 100 kHz toabout 500 kHz. In some embodiments, the laser may be operated in burstmode, with each burst including multiple pulses. In embodiments, thenumber of pulses in the burst may be from 5 to 25. The scan speed may befrom about 100 mm/sec to about 2000 mm/sec or from about 100 mm/sec toabout 800 mm/sec. The number of passes may be from 1 to 15 or 2 to 20.The spot size may be from about 10 μm to about 50 μm. The hatch distancemay be up to about 50 μm, or from about 10 μm to about 30 μm. Inembodiments, the hatch distance may be less than, approximately equalto, or greater than the spot size.

In additional embodiments, operation 1230 may use a femtosecond laserproducing pulses having an effective pulse duration in the femtosecondrange. The femtosecond laser may produce a wavelength in the nearinfrared range. The pulse duration may be from 200 fs to 800 fs, theaverage power may be from about 1 W to about 15 W, and the repetitionrate may be from about 100 kHz to about 750 kHz. In some embodiments,the laser may be operated in burst mode, with each burst includingmultiple pulses. In embodiments, the number of pulses in the burst maybe from 5 to 25. The scan speed may be from about 800 mm/sec to about1200 mm/sec or from about 1000 mm/sec to about 1750 mm/sec, the hatchdistance up to 50 μm, and the number of passes from 1 to 10. The spotsize may be from about 5 μm to about 50 μm.

FIGS. 13A, 13B, 13C, and 13D schematically illustrate three stages in anexample process for forming a marking along an exterior surface of anarticle. FIG. 13A shows a device component 1310 of the article prior toany process operations. The device component 1310 comprises a coating1330 disposed over an exterior surface 1312 of a metal material 1340. Asshown in FIGS. 13A-13D the coating 1330 comprises a first layer 1334 anda second layer 1336. An exterior surface of second layer 1336 forms anexterior surface 1302 of the article. The area over which the marking isto be formed (marking area 1322), the first portion 1331 of the coatingto be removed, and a second portion 1332 of the coating to remain arealso shown.

FIG. 13B shows the device component 1310 of the article partiallythrough the operation of removing the first portion of the coating (1331as shown in FIG. 13A) using the first laser (not shown). Recess 1361 hasbeen formed at a periphery of the marking area 1322 through second layer1336 and a portion of first layer 1334 of the coating 1330. The recess1361 therefore can form an outline for the marking area 1322. Thecoating 1330 is disposed over an exterior surface 1312 of the metalmaterial 1340 and an exterior surface of second layer 1336 forms anexterior surface 1302 of the article.

The operation of removing the first portion of the coating may continueby removing a remainder of the first portion of the coating within theoutline defined by recess 1361 and also below recess 1361. Differentlaser conditions may be used to form the outline than to remove theremainder of the first portion of the coating. In embodiments, the laserused to form the outline may be operated under conditions which minimizedamage to the second layer 1336 in the second portion 1332 of thecoating 1330. For example, the laser used to form the outline may beoperated at a lower power and/or at a lower repetition rate as describedfor the operation 1210 of the process 1200.

As shown in FIG. 13C, the operation of removing the first portion 1331of the coating 1330 in the marking area 1322 may creates a recess 1363extending through the coating 1330 and surrounded by the second portion1332 of the coating 1330. As previously discussed with respect to FIG.12, a first laser may be used to remove the first portion 1331 of thecoating 1330. The second portion 1332 of the coating 1330 surroundingthe recess 1363 defines a recess wall 1364. As shown in FIG. 13D, therecess wall 1364 can be part of the relief feature 1360. In embodiments,the operation of removing the first portion 1331 of the coating 1330produces few, if any, cracks in the recess wall 1364. For example, theoperation of removing the first portion 1331 of the coating 1330 mayproduce a recess wall 1364 which has no cracks visually discernable tothe human eye at a normal viewing distance. Therefore, the multilayercoating may not include visible cracks along the recess wall.

The operation of removing the first portion 1331 of the coating alsocreates an exposed metal portion of the substrate 1340 under the recess1353. As illustrated in FIG. 13C, the exposed metal portion maycorrespond to an exterior surface 1314 of the substrate 1340. Theexterior surface 1314 is not required to be at the same height as theexterior surface 1312 of the metal material 1340 (under the secondportion 1332 of the coating). For example, the operation of removing thefirst portion 1331 of the coating 1330 may cause the exterior surface1314 to be recessed with respect to the exterior surface 1312. In someembodiments, the exterior surface 1314 is recessed by 5 μm or less, 3 μmor less, 2 μm or less, or 1 μm or less with respect to the exteriorsurface 1312.

FIG. 13D shows the device component 1310 after laser texturing withinthe marking area 1322 of the article. As an example, modifying theexposed metal portion/exterior surface 1314 of the substrate 1340creates a recessed marking feature 1366 of the relief feature 1360. Aspreviously discussed with respect to FIG. 12, the exposed metalportion/exterior surface 1314 may be modified using a second laser. Therecessed marking feature 1314 may comprise a geometric feature 1372,such as a groove, formed into the exterior surface 1314 as illustratedin FIG. 13D. As previously described with respect to FIG. 12, therecessed marking feature 1314 may alternately or additionally comprise ametal oxide layer formed along exterior surface 1314. Additionaldescription of features which are shared or similar to those previouslydescribed with respect to any of FIG. 13A-13C is omitted to reduceredundancy.

FIG. 14 illustrates a flowchart of an example process 1400 for forming amarking along an exterior surface of an article. The process 1400 may beused to form a relief feature having a recessed marking feature. Therecessed marking feature may be formed along an exterior surface of anexposed metal portion of a substrate; an oxide layer may be formed alongthe exterior surface of the exposed metal portion to produce a visualeffect. As examples, process 1400 may be used to form the recessedmarking features of FIGS. 6-8.

The operation 1410 of the process 1400 comprises laser ablating thecoating in a marking area of the article. The marking area is along anexterior surface of the article defined by an exterior surface of thecoating. As an example, operation 1410 comprises removing, using a firstlaser, a first portion of the coating. For example, the first laser maybe a femtosecond laser producing pulses having an effective pulseduration in the femtosecond range. The first laser may produce awavelength in the ultraviolet range. The first laser may be operated ina vector mode, a raster mode, or a combination thereof. The laseroperating conditions may be as previously described for the operation1210 of the process 1200 and, for brevity, that description is notrepeated here.

As previously described with respect to the operation 1210 of theprocess 1200, the operation 1410 may comprise ablating an outline in afirst portion of the coating followed by removing a remainder of thefirst portion of the coating. Different laser conditions may be used toform the outline than to remove the remainder of the first portion ofthe coating. For example, the laser conditions may be as described forthe operation 1210 of the process 1210 and, for brevity, thatdescription is not repeated here.

The operation 1410 of removing the first portion of the coating usingthe first laser can form a recess extending through the coating andsurrounded by a second portion of the coating. The operation of removingthe first portion of the coating also can create an exposed metalportion of the substrate under the recess extending through the coating.The operation of removing the first portion of the coating may besimilar to that schematically illustrated by FIGS. 13A, 13B and 13C.

The operation 1420 of the process 1400 comprises laser coloring themarking area. In embodiments, the operation 1420 comprises thermallygrowing a metal oxide layer in the marking area of the article. As anexample, the operation 1420 comprises modifying the exposed metalportion, using a second laser, to create a metal oxide layer along anexterior surface of the exposed metal portion. For example, the secondlaser may be a nanosecond laser producing pulses having an effectivepulse duration in the nanosecond range. The laser may produce awavelength in the near infrared range. In additional embodiments, thesecond layer may be a femtosecond laser producing pulses having aneffective pulse duration in the femtosecond range. The laser conditionsmay be similar to those described for the operation 1230 of the process1200 shown in FIG. 12 and, for brevity, that description is not repeatedhere. In some embodiments, the operation of thermally growing the oxidelayer includes multiple oxide growth operations at different laseroperation conditions, for example at different locations on the exteriorsurface of the metal material.

Process 1400 optionally includes an operation of 1430 of laser texturingthe laser colored marking area. Laser texturing the laser colored areacan comprise ablating a metal oxide or can comprise deeper ablation intothe metal material, such as the metal material below the metal oxide.The operation of laser texturing may use a third laser. For example, thethird laser may be a femtosecond laser producing pulses having aneffective pulse duration in the femtosecond range. The third laser mayproduce a wavelength in the infrared range. The third laser may beoperated in a vector mode, a raster mode, or a combination thereof. Thepulse duration may be from 200 fs to 800 fs, the average power may befrom about 0.01 W to about 15 W or from about 0.05 W to about 5 W, orfrom about 1 W to about 15 W. The repetition rate may be from about 10kHz to about 100 kHz or from about 50 kHz to about 750 kHz. The scanspeed may be from about 200 mm/sec to about 1500 mm/sec, the hatchdistance from about 5 μm to about 30 μm, and the number of passes from 1to 10. The spot size may be from 10 μm to 50 μm. In some embodiments,the laser may be operated in burst mode, with each burst includingmultiple pulses. In embodiments, the number of pulses in the burst maybe from 5 to 25. In some embodiments, the average power may be less thanthat used in the laser coloring operation.

FIG. 15 shows a flowchart of an additional process 1500 for making amarking. The process 1500 includes an operation 1510 of laser ablatingthe coating in a marking area. Process conditions for the operation 1510may be similar to those of the operation 1210 of the process 1200 shownin FIG. 12 and, for brevity, that description is not repeated here.

The process 1500 further includes an operation 1520 of laser shapingand/or texturing the marking area. As an example, the metal portion maybe laser shaped through ablation to form a depression or other geometricshape and then laser textured to polish the laser-formed shape. Theprocess conditions for laser shaping may be similar to those describedfor forming a geometric shape in the operation 1220 of the process 1200of FIG. 12 and, for brevity, that description is not repeated here. Theprocess conditions for laser texturing the marking area may also besimilar to those described for the operation 1220 of the process 1200shown in FIG. 12 and, for brevity, that description is not repeatedhere.

Process 1500 further includes operation 1530 of laser coloring themarking area. Typically, operation 1530 follows operation 1520. Processconditions for the operation 1530 may be similar to those described forthe operation 1230 of the process 1200 shown in FIG. 12.

In addition, process 1500 includes operation 1540 of laser ablatingand/or texturing the marking area following thermal growth of the metaloxide layer. For example, the operation of laser texturing the markingarea may include modifying the metal oxide layer, using a laser, toproduce the recessed marking feature of the relief feature. The lasermay ablate the metal oxide layer to produce one or more desiredthicknesses in the oxide or to produce a geometric feature such as agroove. In embodiments, the laser is a femtosecond laser. The laserconditions may be similar to those described for the operation 1430 ofthe process 1400 shown in FIG. 14 and, for brevity, that description isnot repeated here. In additional embodiments, operation 1540 isoptional.

FIG. 16 is a block diagram of example components of an example articleor electronic device. The schematic representation depicted in FIG. 16may correspond to the article (e.g., an electronic device) depicted inFIGS. 1A-1C as described above. However, the article of FIGS. 1A-1C neednot include all the components shown in FIG. 16. FIG. 16 may also moregenerally represent other types of electronic devices with a marking, asdescribed herein. Further, the marking techniques described herein maybe used to mark a component of the electronic device 1600 including, forexample, the device enclosure, housing, cover, or other device component

As shown in FIG. 16, the electronic device 1600 includes a processor1604 operably connected with a computer-readable memory 1602. Theprocessor 1604 may be operatively connected to the memory 1602 componentvia an electronic bus or bridge. The processor 1604 may be implementedas one or more computer processors or microcontrollers configured toperform operations in response to computer-readable instructions. Theprocessor 1604 may include a central processing unit (CPU) of the device1600. Additionally and/or alternatively, the processor 1604 may includeother electronic circuitry within the device 1600 including applicationspecific integrated chips (ASIC) and other microcontroller devices. Theprocessor 1604 may be configured to perform functionality described inthe examples above. In addition, the processor or other electroniccircuitry within the device may be provided on or coupled to a flexiblecircuit board in order to accommodate folding or bending of theelectronic device.

The memory 1602 may include a variety of types of non-transitorycomputer-readable storage media, including, for example, read accessmemory (RAM), read-only memory (ROM), erasable programmable memory(e.g., EPROM and EEPROM), or flash memory. The memory 1602 is configuredto store computer-readable instructions, sensor values, and otherpersistent software elements

The electronic device 1600 may include control circuitry 1606. Thecontrol circuitry 1606 may be implemented in a single control unit andnot necessarily as distinct electrical circuit elements. As used herein,“control unit” will be used synonymously with “control circuitry.” Thecontrol circuitry 1606 may receive signals from the processor 1604 orfrom other elements of the electronic device 1600.

As shown in FIG. 16, the electronic device 1600 includes a battery 1608that is configured to provide electrical power to the components of theelectronic device 1600. The battery 1608 may include one or more powerstorage cells that are linked together to provide an internal supply ofelectrical power. The battery 1608 may be operatively coupled to powermanagement circuitry that is configured to provide appropriate voltageand power levels for individual components or groups of componentswithin the electronic device 1600. The battery 1608, via powermanagement circuitry, may be configured to receive power from anexternal source, such as an alternating current power outlet. Thebattery 1608 may store received power so that the electronic device 1600may operate without connection to an external power source for anextended period of time, which may range from several hours to severaldays. The battery may be flexible to accommodate bending or flexing ofthe electronic device. For example, the battery may be mounted to aflexible housing or may be mounted to a flexible printed circuit. Insome cases, the battery is formed from flexible anodes and flexiblecathode layers and the battery cell is itself flexible. In some cases,individual battery cells are not flexible, but are attached to aflexible substrate or carrier that allows an array of battery cells tobend or fold around a foldable region of the device.

In some embodiments, the electronic device 1600 includes one or moreinput devices 1610. The input device 1610 is a device that is configuredto receive input from a user or the environment. The input device 1610may include, for example, a push button, a touch-activated button, atouch screen (e.g., a touch-sensitive display or a force-sensitivedisplay), capacitive touch button, dial, crown, or the like. In someembodiments, the input device 1610 may provide a dedicated or primaryfunction, including, for example, a power button, volume buttons, homebuttons, scroll wheels, and camera buttons.

The device 1600 may also include one or more sensors 1620, such as aforce sensor, a capacitive sensor, an accelerometer, a barometer, agyroscope, a proximity sensor, a light sensor, or the like. The sensors1620 may be operably coupled to processing circuitry. In someembodiments, the sensors 1620 may detect deformation and/or changes inconfiguration of the electronic device and be operably coupled toprocessing circuitry which controls the display based on the sensorsignals. In some implementations, output from the sensors 1620 is usedto reconfigure the display output to correspond to an orientation orfolded/unfolded configuration or state of the device. Example sensors1620 for this purpose include accelerometers, gyroscopes, magnetometers,and other similar types of position/orientation sensing devices. Inaddition, the sensors 1620 may include a microphone, acoustic sensor,light sensor, optical facial recognition sensor, or other types ofsensing device.

In some embodiments, the electronic device 1600 includes one or moreoutput devices 1612 configured to provide output to a user. The outputdevice may include display 1614 that renders visual informationgenerated by the processor 1604. The output device may also include oneor more speakers to provide audio output.

The display 1614 may include a liquid-crystal display (LCD),light-emitting diode, organic light-emitting diode (OLED) display, anactive layer organic light emitting diode (AMOLED) display, organicelectroluminescent (EL) display, electrophoretic ink display, or thelike. If the display 1614 is a liquid-crystal display or anelectrophoretic ink display, the display may also include a backlightcomponent that can be controlled to provide variable levels of displaybrightness. If the display 1614 is an organic light-emitting diode ororganic electroluminescent type display, the brightness of the display1614 may be controlled by modifying the electrical signals that areprovided to display elements. In addition, information regardingconfiguration and/or orientation of the electronic device may be used tocontrol the output of the display as described with respect to inputdevices 1610.

In embodiments, an electronic device 1600 may include sensors 1620 toprovide information regarding configuration and/or orientation of theelectronic device in order to control the output of the display. Forexample, a portion of the display 1614 may be turned off, disabled, orput in a low energy state when all or part of the viewable area of thedisplay 1614 is blocked or substantially obscured. As another example,the display 1614 may be adapted to rotate the display of graphicaloutput based on changes in orientation of the device 1600 (e.g., 90degrees or 180 degrees) in response to the device 1600 being rotated.

The electronic device 1600 may also include a communication port 1616that is configured to transmit and/or receive signals or electricalcommunication from an external or separate device. The communicationport 1616 may be configured to couple to an external device via a cable,adaptor, or other type of electrical connector. In some embodiments, thecommunication port 1616 may be used to couple the electronic device to ahost computer.

The electronic device may also include at least one accessory 1618, suchas a camera, a flash for the camera, or other such device. The cameramay be connected to other parts of the electronic device such as thecontrol circuitry.

The following discussion applies to the electronic devices describedherein to the extent that these devices may be used to obtain personallyidentifiable information data. It is well understood that the use ofpersonally identifiable information should follow privacy policies andpractices that are generally recognized as meeting or exceeding industryor governmental requirements for maintaining the privacy of users. Inparticular, personally identifiable information data should be managedand handled so as to minimize risks of unintentional or unauthorizedaccess or use, and the nature of authorized use should be clearlyindicated to users.

The foregoing description, for purposes of explanation, uses specificnomenclature to provide a thorough understanding of the describedembodiments. However, it will be apparent to one skilled in the art thatthe specific details are not required in order to practice the describedembodiments. Thus, the foregoing descriptions of the specificembodiments described herein are presented for purposes of illustrationand description. They are not intended to be exhaustive or to limit theembodiments to the precise forms disclosed. It will be apparent to oneof ordinary skill in the art that many modifications and variations arepossible in view of the above teachings.

What is claimed is:
 1. An electronic device, comprising: a devicecomponent comprising: a metal substrate; a coating layer formed along atleast a front surface of the metal substrate and comprising: a firstlayer disposed over the front surface of the metal substrate andcomprising a polymer binder and inorganic pigment particles dispersedwithin the polymer binder; and a second layer disposed over the firstlayer and comprising a transparent polymer defining at least a portionof an exterior surface of the electronic device; and a marking formedalong the exterior surface and comprising a laser-formed relief featurehaving: at least one recess wall partially defining a recess extendingthrough the first layer and the second layer; and a recessed markingfeature defining a bottom of the recess and visually distinct from anadjacent portion of the coating layer.
 2. The electronic device of claim1, wherein: the recessed marking feature includes an oxide layer formedover the metal substrate; and a color of the recessed marking feature isdue, at least in part, to a thickness of the oxide layer.
 3. Theelectronic device of claim 1, wherein: the laser-formed relief featureincludes: a groove extending into the metal substrate and defining apair of groove walls; a first metal oxide layer extending along a firstwall of the pair of groove walls and having a first thickness defining,in part, a first color; and a second metal oxide layer formed along asecond wall of the pair of groove walls, having a second thicknessdifferent from the first thickness, and defining, in part, a secondcolor.
 4. The electronic device of claim 3, wherein an apparent color ofthe recessed marking feature is due to a combined effect of the firstcolor and the second color.
 5. The electronic device of claim 3,wherein: the groove is v-shaped; and an angle defined between the firstgroove wall and the second groove wall is from about 60 degrees to about120 degrees.
 6. The electronic device of claim 1, wherein thelaser-formed relief feature further comprises a depression formed intothe metal substrate.
 7. The electronic device of claim 6, wherein adepth of the depression is less than 500 μm.
 8. The electronic device ofclaim 1, wherein: the recessed marking feature comprises a texture alongthe front surface of the metal substrate; and the texture defines, atleast in part, a reflectance of the recessed marking feature.
 9. Anelectronic device comprising: a device component comprising: a metalmaterial; a multilayer coating formed over a surface of the metalmaterial and comprising: a first layer disposed over the surface of themetal material and comprising a binder and pigment particles dispersedwithin the binder; and a second layer disposed over the first layer andcomprising a transparent polymer; and a marking formed into themultilayer coating and comprising: a first recessed marking featurealong the surface of the metal material and visually distinct from themultilayer coating; and a laser-formed relief feature at least partiallysurrounding the first recessed marking feature and having: a recess wallpartially defining a recess extending through the first layer and thesecond layer of the multilayer coating; and a second recessed markingfeature visually distinct from an adjacent portion of the multilayercoating and defining, in part, a bottom of the recess.
 10. Theelectronic device of claim 9, wherein: the first recessed markingfeature further comprises a metal oxide layer formed along the surfaceof the metal material; and the first recessed marking feature has amarking color defined, at least in part, by a thickness of the metaloxide layer.
 11. The electronic device of claim 9, wherein the firstrecessed marking feature further comprises: a first metal oxide layeralong a first region of the surface of the metal material and having afirst thickness; a second metal oxide layer along a second region of thesurface of the metal material and having a second thickness; and thefirst recessed marking feature has a first marking color defined, atleast in part, by the first thickness and a second marking colordefined, at least in part, by the second thickness.
 12. The electronicdevice of claim 9, wherein the second recessed marking feature comprisesa geometric feature formed into the metal material.
 13. The electronicdevice of claim 9, wherein: the pigment particles are titanium dioxideparticles; and the marking further comprises a color feature formed, inpart, at an interface between the first layer and the second layer. 14.The electronic device of claim 9, wherein the multilayer coating doesnot include visible cracks along the recess wall.
 15. A method forforming a marking comprising a relief feature along an exterior surfaceof an electronic device, the method comprising: removing, using a firstlaser, a portion of a multilayer coating to form a recess through themultilayer coating and expose a metal portion of a substrate, themultilayer coating formed over a surface of the substrate andcomprising: a first layer comprising a binder and inorganic pigmentparticles within the binder; and a second layer disposed over the firstlayer and comprising a transparent polymer; and modifying the metalportion, using a second laser, to create a recessed marking featurecomprising at least one of: a geometric feature formed into a surface ofthe metal portion; or a metal oxide layer formed along the surface ofthe metal portion.
 16. The method of claim 15, wherein the first laserproduces pulses having a duration in a femtosecond range and awavelength in an ultraviolet range.
 17. The method of claim 15, whereinthe second laser produces pulses having a duration in a nanosecond rangeand a wavelength in an infrared range.
 18. The method of claim 15,wherein: the second layer has a hardness greater than a hardness of thefirst layer; the recess is at least partially defined by a recess wallformed in the multilayer coating; and the recess wall is substantiallyfree from cracks or visual defects.
 19. The method of claim 15, furthercomprising laser texturing the metal portion, using a third laser, thelaser texturing performed prior to forming the metal oxide layer. 20.The method of claim 15, wherein: the operation of modifying the metalportion, using the second laser, creates the recessed marking featurecomprising the metal oxide layer formed along the surface of the metalportion; and the method further comprises the operation of forming,using a third laser, a geometric feature in the metal oxide layer.